Colloidal semiconductor nanocrystals are typically comprised of a semiconducting core and the ligand shell, passivating the surface. The effective size of such assembly is dictated by the size of the core and the length of the ligand. As deposited on the substrate, the length of the ligands will determine the space occupied by the quantum dot.
The length of the ligands, however, diminishes the efficiency of charge extraction from the nanocrystal. Accordingly, there is a need in the art for quantum dot devices that exhibit improved charge extraction.